Particularly in the case of Internet-based applications, it is common to house servers hosting such applications in data centers. Because of the centralization of these computing resources in data centers, which may house hundreds of computing devices such as servers in a relatively small physical space, heat management and thermal efficiency of such data centers has become a significant issue. Indeed, it is estimated that the power needed to dissipate heat generated by components of a typical data center is equal to approximately 50% of the power needed to actually operate those components (see U.S. Published Patent Appl. No. 2005/0228618, at paragraph 0002).
Further, even in discrete areas of a data center, localized areas of thermal stress, or “hot spots,” may occur. This is because in a typical data center configuration, computing devices such as servers are typically housed in racks of known design. Because of considerations such as distance from cooling units and/or air movement devices, particular areas of a data center may be significantly hotter than others. For example, the temperature at a top of a rack may be significantly higher than the temperature at the bottom of the same rack, due to the rising of heated air and potentially a distance of the top of the rack from a source of cooling or air movement compared to the bottom of the same rack. Even more, a rack which houses a number of servers which are powered on and hosting computing workloads will likely generate more heat than a corresponding rack in the same area of the data center with fewer servers, or which is hosting fewer computing workloads.
Traditionally, to address this issue of thermal stress or “hot spots,” hardware-based methods have been utilized i.e., increasing cooling parameters in the data center, powering down computing resources located in areas of thermal stress, and the like. Alternatively, it is known to pre-allocate computing resources according to a variety of parameters including computing capacity and temperature considerations (for example, see U.S. Published Patent Application No. 2005/0228618). Thus, while it is known to address thermal stress in data centers proactively, conventional reactive means (that is, detecting and addressing existing or newly created thermal stress in a data center) are typically limited to hardware solutions.
However, a variety of situations may arise where more efficient and economical reactive means for addressing newly created thermal stress in a data center are desirable, particularly in the case where computing resources have been provisioned and the thermal stress does not occur or is not detected until well after such provisioning. For example, human or even computer error may result in over-provisioning workloads to particular servers located in a common area of a data center, resulting in a “hot spot.” Alternatively, a cooling unit in a particular area of a data center may fail or be functioning at a reduced efficiency, resulting in a “hot spot.”
There accordingly remains a need in the art for methods for addressing such thermal stress issues, to allow real- or near-real time improvements in thermal efficiency of the data center without need for altering cooling capacity or powering down computing resources. In particular, improved reactive methods for addressing existing or newly created thermal stress are desirable. Any improvements along such lines should further contemplate good engineering practices, such as relative inexpensiveness, stability, ease of implementation, low complexity, security, unobtrusiveness, etc.